SE Rocket build - The Wrong Horse Amp

[Faze]

This is a damn good sounding little amp. As soon as I’m done with my tweed champ, I’m working on one of these. Nice job Niki.

[Synchu]

Thanks! It’s a fine little amp indeed and fun to build
Niki

[leadfootdriver]

This thing is awesome. It sounds like it can get gainy without the cops showing up..
Any updates or new recordings with this?!?!

[Synchu]

This thing is awesome. It sounds like it can get gainy without the cops showing up..
Any updates or new recordings with this?!?!

Ahh ... didn't see this.
Not really, but may look to do something in the following weeks.
With an efficient speaker, it can be quite grumpy

Niki

[Synchu]

While this has been brought back - I took it out of the box and did some further tweaks, changed the first coupling cap to 0.01uF to pass a bit more low/mid end, changed the power tube grid stopper to 5.6K, and converted the heater supply to DC.
Sounds even better (to me at least).

Also tested an exchange of the ancient radio output transformer with a SE Edcor I had, but quickly switched back Sounds best as it was.

Here's a new one (humbucker-equipped guitar - Washburn N4 - all tracks - lead is with Vol at about 3 o'clock, rhythm is around 10 o'clock with just a tiny bit of Bogner Harlow pedal - boost/compressor type).
https://soundcloud.com/synchu/june-of-rain-v5

Niki

[fabiomayo]

Sounding killer!! Love it!

[ChopSauce]

... changed the first coupling cap to 0.01uF ...

I think I can ear that ...
(& love it too)

How about the DC heaters: way less hum, or just slight improvement?

One more thing I've always been curious about: with comparable voltages, "your" resistor value for the power tube is twice "mine" and the dissipation seems to be similar in both cases...

[Synchu]

Thanks guys! Appreciated!

... changed the first coupling cap to 0.01uF ...

I think I can ear that ...
(& love it too)

How about the DC heaters: way less hum, or just slight improvement?

One more thing I've always been curious about: with comparable voltages, "your" resistor value for the power tube is twice "mine" and the dissipation seems to be similar in both cases...

DC heaters made a noticeable difference. It is not like a night and day thing, but my experience with SE amps is that they are generally more sensitive to heaters induced noise - so it worked quite good. This old trafos don't help with the noise as well (The output transformer "sings" big time when the amp is cranked.)

Now with the voltage thing - I really don't know what the OT primary is - the old radio it was scavenged from had a single EL84, but I can remember very different voltages on its schematic - can't remember the exact numbers, but definitely not in the 300+ range.

As long it sounds good - it is good

Niki

[leadfootdriver]

That's a nice tone you have going on there!

[bepone]

DC heaters made a noticeable difference. It is not like a night and day thing, but my experience with SE amps is that they are generally more sensitive to heaters induced noise - so it worked quite good. This old trafos don't help with the noise as well (The output transformer "sings" big time when the amp is cranked.)

Now with the voltage thing - I really don't know what the OT primary is - the old radio it was scavenged from had a single EL84, but I can remember very different voltages on its schematic - can't remember the exact numbers, but definitely not in the 300+ range.

As long it sounds good - it is good

it sounds good,
i like the use of old radio transformer, it is nice filter, it rolls off bass and highs, perfect for guitar use..

to reduce humm even more, for SE you need to improve filtering before OPT, like this per example, with adding cheap R+C combo you will kill a lot of humm

rc.png

[Synchu]

Thanks for the note!
It's been a while since I called it a day with this one

To be honest - I did quite a bit of experimentation, including chokes, etc. and there's no noticeable change (that does not impact the sound as well). It is reasonably quiet, even cranked and sounds great so happy for now (things change though ).

Niki

[ChopSauce]

As you're there - or around: any comments about the pseudo/half-PI, as it was made switchable - if I remember well ; worthy or not?

[Synchu]

I leave it off most of the time as I like it on the cleanish side.
It provides for a good bump in volume and gain so definitely usable for leads and if (for whatever reason) somebody decides to build it for anything different than recording (it is great for that)/practice, I'd put that on a foot pedal (and call it PIB - PI boost)

Niki